Improvement in safety-valves



UNITED STATES QFFIGE.

HIRAM r. cAsn, 0F DETROIT, AND ROBERT P. BAILLIE, or rnnavsnune,

MICHIGAN.

IMPROVEMENT IN SAFETY-VALVES.

Specification forming part of Letters Patent No. 146,314., dated January 13, 1874 application filed December 16,1873.

To all whom it may concern:

Be it known that we, HIRAM P. CASE, of Detroit, in the county of Wayne, and ROBERT P. BAILLIE, of Ferrysburg, in the county of Ottawa and State of Michigan, have invented an Improvement in Safety-Valves, of which the following is a specification:

The nature of this invention relates to an improvement in that class of safety-valves which are provided with two faces inclined to each other and seating against corresponding faces in the valve-seat; and its object is to provide an adjustable outer seat, which can be adjusted with relation to the outer face of the valve, to partially arrest the outflow of the escaping steam, which, thus acting upon an increased valve area, lifts the valve to a full opening; and it consists inaclamp-nut threaded on the outside of the valve-seat collar and provided with a seat, as more fully hereinafter set forth.

face of the collar is screw-threaded to receive a clamp-nut, 0, having its upper end chamfered to form an inclined seat, 0, the valve being provided with a corresponding face, 0. The nut is provided with alug, d, which, after thethread is cut in the nut, is slit, and a screw, 0, tapped transversely through both parts, and by means of which the nut may be immova bl y clamped in place on the collar of the valveseat.

The nut should be so adjusted as to bring its seat a barely into contact with the face 0 of the valve when seated, and then clamped fast in that position, in which it will not interfere with the seating of the valve upon the horizontal inner seat I), so that, whenever the pressure upon the valve exceeds its load, it will lift a little, and the outflow of the steam being retarded or partially arrested by the diminished area of opening between the seat and face a c as compared with the opening between b 1), thereby offering an increased valve area to the steam pressure, the valve will at once lift to a full opening, and, when the boilerpressure falls below the load of the valve, the

latter will immediately seat itself, and thus prevent any unnecessary blowing ofl.

In thus describing the action of such a valve, we do not wish to be considered as claimants of the invention thereof in this connection; but we include such description for the purpose of more fully showing the advantage of our ad-f the manufacturer to ease off the outer valveface before the inner one could be ground to lts seat, and necessitating tests under steam to in sure accuracy in operation.

With our improvement the valve may be first faced to the nut, and the latter be run down to allow the valve to be ground to its proper seat, after which the nut is adjusted to serve as a chokeoif for the escaping steam, as hereinbefore described.

We are well aware that a plain nut with a jam-nut under it may be used in place of the clamp-nut C; but the jam-nut would be objectionable and inconvenient on account of the projecting stud-bolts which secure the yoke, or a lock-up case, if one be used, and which would render it diflieult to turn the said jamnut, besides increasing the height of the seatcollar.

What we claim as our invention, and desire to secure by Letters Patent, is

The adjustable clamp-nut G, screwed on the collar a exterior to the valve-seat b, and provided with the inclined seat 0, in combination with the an gular-faced valve B, substantially as and for the purpose set forth.

HIRAM P. CASE. ROBERT P. BAILLIE.

ANDW. TI-rOMsoN. 

